Technical Field
The present invention relates to an ink, an ink container, an inkjet recording method, an inkjet recording device, and recorded matter.
Description of the Related Art
Since inkjet printers are relatively quiet, enjoy low running costs, and are capable of easily printing color images, they are now widely used at home as an output device of digital signals.
In recent years, such inkjet technologies have been appealing in business fields of, for example, display, posters, and signboards in addition to home use.
However, recording media for industrial use are not limited to paper, but can include anything from paper to transparent articles to colored articles. To represent white on such recording media or color it with color ink, it is necessary to conceal transparency of a recording medium or sufficiently conceal the color of a recording medium with ink. For this reason, white ink is used to cover such transparent or colored media with white. In addition, when color ink is used, in order to use the same color ink for use in typical images, the surface of a recording medium is printed with white ink as backdrop for the color ink to enhance coloring.
As the pigment for such white ink, titanium dioxide is popular, which is excellent white pigment in terms of concealing property and coloring property. To demonstrate good concealing property using titanium dioxide, dispersing particles in a particle size range of from 200 to 400 mn is required to scatter visible light. However, titanium oxide tends to settle out because of its great specific gravity in comparison with that of an ink medium. Moreover, titanium dioxide settles out faster in low viscous ink such as aqueous ink and solvent ink. Furthermore, titanium dioxide that has settled out takes the closest packing structure, so that re-dispersion of titanium dioxide is difficult.
To deal with such issues, ink using hollow particles have been developed. Since an ink medium is present in the hollow portion of hollow particles in ink, specific gravity thereof decreases in appearance and the hollow particle does not easily settle out. Moreover, concealment by hollow particles is obtained by utilizing the difference of refractive index between hollow shells and the hollow portion from which the ink medium is drawn out after applied film is dried.
For example, ink including organic particles having a hollow structure and inorganic particles having a hollow structure has been proposed.